retroworks writes: "Rebecca J. Rosen interviews experts in this edtion of The Atlantic, to ask about the ethics and wisdom of using cloning, backbreeding, or genome editing. Over 90% of species ever to exist on earth are no more. The article ponders the moral and environmental challenges of humans reintroducing species which humans made extinct."Link to Original Source

There are plenty of people who get irate at the notion of allowing human activity to result in the extinction of a species. Surely resurrecting such a species is merely an effort to undo the damage caused? As for species that died out naturally, well again - why not? So long as we're wise enough not to introduce a new predator into an ecosystem, or such like.